< How it Works

Based on Your Body's Own Symptoms

Lily's symptoms-based cycle evaluation methods are based on the most popular sympto-thermal methods (STM) FAM (Fertility Awareness Method) and AG NFP (Natural Family Planning) as both combine the evaluation of cervical fluid and the basal body temperature.

These sympto-thermal methods help a woman identify which days of her cycle are her fertile, and wich ones are her infertile days. Pregnancy achievers as well as pregnancy avoiders benefit from this knowledge, as they can time intercourse around these phases to meet their needs.

How it Works

FAM and NFP rely on the assumption that an egg (ovum) can be fertilized between twelve to 24 hours after ovulation, that sperm can survive in the vagina for up to five days under ideal circumstances, and that a pregnancy is possible due to intercourse two to three days before and after ovulation.

Since the exact time of ovulation can only be identified in retrospective, Lily adds two to three days prior to and following your thermal shift in order to time intercourse to conceive, or to identify your infertile phase for those using Lily as a birth-control method.


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We do not guarantee the method of birth control or pregnancy achievement as described on this web site.

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